docs: confirm the reMarkable 2 runs the app on hardware

[partridgeworks]

What changed

The reMarkable 2 row in the README's supported-models table, and the matching
row in docs/compatibility.md, no longer say "not yet confirmed on hardware /
testers wanted". Both now record that the app is confirmed running on a
reMarkable 2, scoped to what has actually been exercised.

Why

You note in the README that you own a Paper Pro and nothing else, so the other
models depend on community testing. This is that report: I've been running the
app daily on a reMarkable 2 (reMarkable 2.0, armv7l) on OS 3.27.3.0, where
it fetches from the Device API and renders real dashboards on the greyscale
panel without trouble.

I've deliberately not claimed the model as fully validated. The checklist at
the bottom of docs/compatibility.md asks for a good deal more than I've done —
offline restart from cache, overlay cleanup, suspend and resume, reboot to
stock, reactivation, uninstall, purge, and stock recovery — and none of that is
confirmed on this model. The wording says so plainly, and links to that
checklist, so the gap is visible rather than papered over. The reMarkable 1 row
is untouched.

Two caveats worth your judgement:

• My install was done with reManager, not this project's own installer and
  release archive, so I cannot give you an archive SHA-256 and this is not
  evidence for the exact-archive install path the checklist asks about.
• Tell me if you'd rather this stayed as "testers wanted" until the whole
  checklist is done. I'd rather under-claim than have the table promise more
  than has been tested — reword or close it as you see fit.

Validation

• gofmt, unit tests, race tests, and go vet — unaffected; documentation only, no code changes
• ShellCheck, QML lint/resources, and AppLoad protocol integration — not applicable, no shell, QML, or protocol files touched
• ARM64 build and govulncheck — unaffected, no code changes
• Physical Paper Pro evidence — not applicable, no Paper Pro. The change reports reMarkable 2 evidence, described above
• Recovery/rollback behavior documented for device-changing work — not applicable, nothing on the device changes
• No credentials, private captures, downloads, tools, or generated artifacts

Compatibility and recovery impact

None. Documentation only: no code, no persistent file changes, no change to
installer behaviour, and nothing to recover from. The model and firmware gates
are untouched — this records evidence about a device the installer already
accepts, and does not widen what it will install onto.

[partridgeworks]

Hey there - just getting in touch to confirm that I have tested this app on the rm2 and have it running locally, fetching TRMNL pages from a BYOS server. (on my LAN)

The PR itself is generated by Claude Code (not trying to hide that) but I worked with it to test locally and confirm, so if you're happy on that basis then this amends the README with the current status.